Radiation therapy is, and will continue to be, an important modality of cancer treatment so that an understanding of mechanisms by which agents modify the response of various tissues and tumors is important. Furthermore, exposure to low doses of radiation of different quality through environmental and diagnostic medical exposure require a formal assessment of the associated risks and genetic hazards. Since the effects of ionizing radiation on DNA lie at the root of these biological effects, it is the aim of this meeting to bring together experts in physics, chemistry and biology who have a common interest in understanding the effects of ionizing radiation on DNA with the objective of assessing the current state of knowledge. Through structured discussions and interchanging of ideas, it is intended that a common dialogue may be developed with the objective of identifying the most important areas of future research based upon an interdisciplinary approach. A number of young scientists active in this field will be encouraged to attend and contribute to the meeting through oral presentations. There have been important recent advances in the field of radiation damage to DNA: such as the development of powerful computer methods to simulate energy deposition events and complex ESR spectra, mono-energetic particle beam and ultrasoft x-ray techniques, analytical methods for study of DNA damage at low and biologically relevant doses, improved characterization of radiation induced free radicals in DNA, and the application of molecular biology techniques. It is timely to bring this advanced knowledge together through an interdisciplinary meeting. An important role of this meeting is to decrease polarization by discipline and stimulate new approaches by scientists who become aware of the relevance of the findings from other projects to their own work. Although the focus of individual approaches spans physics, chemistry, and biology, the common goal of all participants is to understand the biological endpoints in terms of predictable alterations in DNA. To this end, an effort will be made to work on a common language, between the physicists and chemists, with the objective of facilitating communication with investigators working on biological endpoints. The publication of the proceedings will provide biologists with a much needed update on the state of knowledge on the chemical and physical basis of DNA damage.